Trough, Oscillating and Cannon Balls, 71 U. S. Patents, 36, 38, 76 Vacuum Engine, Orchard's, 137 Vallance, Dixon, His Device, 34 Varley, Richard, His "New Perpetual Moving Power", 132 Vinci, Leonardo da, Notice of, 27 His Perpetual Motion Labors, 29, 32 "Voice of Reason," Device by Author of, 88 Vogel, A. F., His "Hydrostatic General Mobile", 96 Water Blowing Machine, 147 Water-Wheel Driven Pump, 97 Welch, J., Article by, 351 Wheel, Magnetic Driven (See Magnetic-Driven Wheel). Wheels and Weights Devices (See Table of Contents), 5 Wilckens (See Ludeke and Wilckens). Wilkins, Rev. John, Argument Denying Possibility of Perpetual Motion, 281 Worcester, Marquis of (Edward Sommerset) (See Sommerset). X-Ray Machine, Notice of, 16 Transcribers' Notes: In Unicode and HTML versions of this eBook, Greek words are shown in Greek and then in Transcribers' English transliterations that are enclosed in {curly braces}. Only the transliterations are shown in Latin-1 and ASCII versions of this eBook. Individual Greek letters used in equations and lists are shown either as actual Greek letters or in similar Latin characters, depending on the version of this eBook. Also see later note about alchemy symbols. Accent mark errors in Greek text have been remedied. Inconsistent spelling and punctuation have been retained, as this book quotes many sources. Simple typographical errors were corrected. Ambiguous hyphens at the ends of lines were retained. The original book copied illustrations from various sources and did not change the Figure numbers. This eBook retains those original identifications, so there are duplicate numbers. Text usually spells "Galileo" as "Gallileo"; both forms have been retained here. Mathematical equations have been expressed here in linear form. Accuracy of their transcriptions is questionable. Multiplication was indicated in various ways and has not been changed or standardized. Page 73: "phraseology" was printed as "praseology". Page 76: "1882" was printed as "182". Page 222: "misspent" was printed as "mispent". Page 229: "perseverance" was printed as "perserverance". Page 220 and others: "'s Gravesande" was the person's name. Page 241: Removed unmatched double quote mark following "it only turns one way." Page 252: Removed unmatched double quote mark following "should be undeceived."